Fasting Serum Free Fatty Acid Research Articles

Serum free fatty acid level in children with primary hypertension

To examine the serum level of free fatty acid (FFA) in children with primary hypertension and its value in the pathogenesis, prevention, and treatment of primary hypertension in children. In this retrospective study, 34 children with primary hypertension who were treated for the first time in Children's Hospital Affiliated to Capital Institute of Pediatrics from January to June, 2021, were enrolled as the hypertension group, and 32 children with normal blood pressure who underwent physical examination during the same period were enrolled as the control group. The two groups were compared in terms of the levels of fasting serum FFA, fasting serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C). The multivariate logistic regression model was used to analyze the influence of FFA on the development of primary hypertension. Compared with the control group, the hypertension group had significantly higher body mass index (BMI), systolic blood pressure, and diastolic blood pressure (P<0.05), as well as significantly higher serum levels of FFA, TG, LDL-C, and non-HDL-C and a significantly lower serum level of HDL-C (P<0.05). Compared with the control group, the hypertension group had significantly higher rates of elevated serum FFA (>0.45 mmol/L for girls and >0.60 mmol/L for boys) (P<0.05) and abnormal blood lipid levels (abnormality in at least one index among serum TG, TC, LDL-C, HDL-C, and non-HDL-C) (P<0.05). A multivariate logistic regression equation was established based on age, sex, BMI, elevated serum FFA, and abnormal blood lipid levels, and the results showed that elevated serum FFA was an independent risk factor for primary hypertension in children (OR=17.560, 95%CI: 1.964-157.003, P<0.05). There is a significant increase in serum FFA level in children with primary hypertension, and the increase in serum FFA can increase the risk of primary hypertension in children.

Basal insulin ameliorates post-breakfast hyperglycemia via suppression of post-breakfast proinsulin/C-peptide ratio and fasting serum free fatty acid levels in patients with type 2 diabetes.

In general, basal insulin targets fasting plasma glucose (FPG) levels, and prandial insulin targets postprandial glucose (PPG) levels. However, the effects of basal insulin on PPG levels are controversial. We investigated the effect of basal insulin on postprandial hyperglycemia using a test meal at breakfast as well as compared differences between degludec and glargine. A total of 20 participants with type 2 diabetes were randomly assigned to degludec (n = 10) or glargine (n = 10). We initiated basal-bolus insulin therapy and titrated only basal insulin until FPG was < 6.1mmol/L. We evaluated changes in post-breakfast glucose levels and changes in clinical parameters such as serum C-peptide (CPR), proinsulin (PI), and free fatty acids (FFA) levels between the pre- and post-titration periods. Differences between degludec and glargine in the post-titration period were also evaluated. Post-breakfast glucose levels significantly decreased by 46.1% in the post-titration period compared with the pre-titration period (n = 20, p < 0.001). These decreases correlated positively with decreases in the post-breakfast PI/CPR ratio (r = 0.692, p < 0.001) and in fasting FFA levels (r = 0.720, p < 0.001). There were no significant differences in post-breakfast glucose levels between degludec and glargine. However, the hypoglycemic rate with degludec was significantly lower than with glargine. Our results suggest that basal insulin with either degludec or glargine decreases the incidence of post-breakfast hyperglycemia accompanied by decreasing the post-breakfast PI/CPR ratio and fasting FFA levels in patients with type 2 diabetes.

Autologous subcutaneous adipose tissue transplants improve adipose tissue metabolism and reduce insulin resistance and fatty liver in diet-induced obesity rats.

Long‐term dietary and pharmacological treatments for obesity have been questioned, particularly in individuals with severe obesity, so a new approach may involve adipose tissue transplants, particularly autologous transplants. Thus, the aim of this study was to evaluate the metabolic effects of autologous subcutaneous adipose tissue (SAT) transplants into two specific intraabdominal cavity sites (omental and retroperitoneal) after 90 days. The study was performed using two different diet‐induced obesity (DIO) rat models: one using a high‐fat diet (HFD) and the other using a high‐carbohydrate diet (HCHD). Autologous SAT transplant reduced hypertrophic adipocytes, improved insulin sensitivity, reduced hepatic lipid content, and fasting serum‐free fatty acids (FFAs) concentrations in the two DIO models. In addition, the reductions in FFAs and glycerol were accompanied by a greater reduction in lipolysis, assessed via the phosphorylation status of HSL, in the transplanted adipose tissue localized in the omentum compared with that localized in the retroperitoneal compartment. Therefore, the improvement in hepatic lipid content after autologous SAT transplant may be partially attributed to a reduction in lipolysis in the transplanted adipose tissue in the omentum due to the direct drainage of FFAs into the liver. The HCHD resulted in elevated fasting and postprandial serum insulin levels, which were dramatically reduced by the autologous SAT transplant. In conclusion, the specific intraabdominal localization of the autologous SAT transplant improved the carbohydrate and lipid metabolism of adipose tissue in obese rats and selectively corrected the metabolic parameters that are dependent on the type of diet used to generate the DIO model.

Correlation between serum free fatty acid level and estimated glomerular filtration rate in type 2 diabetic patients

To investigate the relationship between serum free fatty acid (FFA) level and glomerular filtration rate (GFR) in patients with type 2 diabetes mellitus (T2DM). A total of 442 T2DM patients treated in Sir Run Run Shaw Hospital from January 2013 to June 2015 were retrospectively analyzed and divided into three groups according to estimated glomerular filtration rate (eGFR) levels using modified modification of diet in renal disease (MDRD) formula: eGFR≥90 ml·min(-1)·1.73 m(-2)group (group A, 227 cases), 60 ml·min(-1)·1.73 m(-2)≤eGFR<90 ml·min(-1)·1.73 m(-2)group (group B, 118 cases), and eGFR<60 ml·min(-1)·1.73 m(-2)group (group C, 97 cases). In addition, 50 body mass index (BMI)-matched non-diabetic subjects were selected as control group. Fasting serum FFA level was measured in each group, and its relationship with eGFR was analyzed. FFA level in group C[(450±203)μmol/L]was significantly higher than that in group A[(326±167)μmol/L], group B[(394±184)μmol/L]and control group[(320±90)μmol/L](all P<0.05). Meanwhile, FFA level in group B was higher compared with that in group A (P<0.05). However, no statistical difference was found in FFA level between group A and Control group (P>0.05). Multiple linear regression analysis using eGFR as the dependent variable demonstrated that uric acid (UA), FFA, triglyceride (TG), total cholesterol (TC), albuminuria, hypertension, smoking and duration of diabetes were all independent risk factors for decreased eGFR (all P<0.05). The present results suggest that increased FFA level might be involved in the development of diabetic nephropathy.

Association between serum free fatty acid levels and nonalcoholic fatty liver disease: a cross-sectional study.

High serum free fatty acid (FFA) levels are associated with metabolic syndrome (MS). This study aimed to assess the association of fasting serum FFAs with nonalcoholic fatty liver disease (NAFLD) in a Chinese population. A total of 840 subjects fulfilled the diagnostic criteria of NAFLD and 331 healthy control participants were enrolled in this cross-sectional study. Fasting serum FFA levels and other clinical and laboratory parameters were measured. NAFLD patients had significantly higher serum FFA levels than controls (P < 0.001). Serum FFA levels were significantly and positively correlated with parameters of MS, inflammation indexes, and markers of hepatocellular damage. Elevated serum FFA levels were found in NAFLD subjects with individual components of MS (obesity, hypertriglyceridaemia, and hyperglycaemia). Stepwise regression showed that serum FFA levels were an independent factor predicting advanced fibrosis (FIB-4 ≥ 1.3) in NAFLD patients. Serum FFA levels correlated with NAFLD and could be used as an indicator for predicting advanced fibrosis in NAFLD patients.

Effects of indigestible carbohydrates in barley on glucose metabolism, appetite and voluntary food intake over 16 h in healthy adults

BackgroundRecent knowledge in animals suggests that gut microbial metabolism may affect host metabolism, including appetite regulating hormones. The aim of the present study was to evaluate the potential effects of a whole grain barley kernel product, rich in intrinsic indigestible carbohydrates (dietary fibre and resistant starch), on markers of metabolism and appetite regulation in healthy subjects.MethodsBoiled barley kernels (BK) or white wheat bread (WWB; reference) were provided as late evening meals to 19 young adults in random order using a cross-over design. During subsequent ad libitum standardized breakfast and lunch meals (10.5-16 h), blood was collected for analysis of glucose, plasma insulin, adiponectin, ghrelin, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), serum free fatty acids (FFA) and interleukin (IL)-6. In addition, appetite sensations, voluntary energy intake and breath H2 were determined.ResultsBK as evening meal increased plasma GLP-1 at fasting (P < 0.05) and during the experimental day (P < 0.01) compared with WWB. In addition the BK evening meal decreased fasting serum FFA (P < 0.05) and tended to decrease fasting serum IL-6 (P = 0.06). At lunch, preceded by BK evening meal, voluntary energy intake was decreased (P < 0.05) when compared to WWB evening meal. The BK evening meal decreased incremental blood glucose area (P < 0.01), promoted higher breath H2 (P < 0.001), maintained adiponectin concentrations (P < 0.05) and reduced perceived hunger (P < 0.05) during 10.5-16 h after the meal.ConclusionsThe results indicate that the BK evening meal, facilitate glucose regulation, increase the release of GLP-1, reduce subsequent energy intake while at the same time decreasing hunger over 2 subsequent meals, and reduce fasting FFA the subsequent morning, possibly mediated through gut microbial fermentation of the indigestible carbohydrates.

Plasma Free Myristic Acid Proportion Is a Predictor of Nonalcoholic Steatohepatitis

Serum free fatty acid (FFA) composition and abnormal fatty acid metabolism have been implicated in the pathogenesis of nonalcoholic steatohepatitis (NASH). Therefore, we determined if the serum FFA composition can provide accurate diagnosis of NASH. We compared fasting serum FFA compositions in 20 patients with simple steatosis to those in 77 patients with NASH, including 65 patients with early-stage NASH. By univariate analysis, the proportions of serum free myristic acid (P=0.002) and palmitoleic acid (P=0.033) and the stearoyl CoA desaturase (SCD)-1 index (P=0.047) were significantly elevated in NASH patients in comparison to patients with simple steatosis. Only the serum free myristic acid proportion was significantly elevated in the early-stage NASH group in comparison to the simple steatosis group (P=0.003). Multiple logistic regression analysis demonstrated that the serum free myristic acid proportion was significantly elevated in all patients with NASH (P=0.011) and the subset of patients with early-stage NASH (P=0.012) in comparison to those with simple steatosis. The area under the curve (AUC) for the serum free myristic acid proportion was 0.734 to detect NASH and 0.719 to detect early-stage NASH in comparison to simple steatosis. Serum free myristic acid proportion could be a useful independent predictor to differentiate NASH from simple steatosis.

Improved n-3 fatty acid status does not modulate insulin resistance in fa/fa Zucker rats

The objective was to examine the effect of polyunsaturated fatty acid type (plant vs fish oil-derived n-3, compared to n-6 fatty acids in the presence of constant proportions of saturated, monounsaturated and polyunsaturated fatty acids) on obesity, insulin resistance and tissue fatty acid composition in genetically obese rats. Six-week-old fa/fa and lean Zucker rats were fed with a 10% (w/w) mixed fat diet containing predominantly flax-seed, menhaden or safflower oils for 9 weeks. There was no effect of dietary lipid on obesity, oral glucose tolerance (except t=60 min insulin), pancreatic function or molecular markers related to insulin, glucose and lipid metabolism, despite increased n-3 fatty acids in muscle and adipose tissue. The menhaden oil diet reduced fasting serum free fatty acids in both fa/fa and lean rats. These data suggest that n-3 composition does not alter obesity and insulin resistance in the fa/fa Zucker rat model when dietary lipid classes are balanced.

Fasting Serum Free Fatty Acid Composition, Waist/Hip Ratio and Insulin Activity in Essential Hypertensive Patients

Abnormal fatty acid metabolism may play an important role in the pathogenesis of essential hypertension (EH). We compared fasting serum free fatty acid (FFA) composition between EH patients and nonhypertensive (NH) subjects, and examined the relationships between fasting serum FFA composition and waist/hip ratio, insulin activity, blood pressure, serum zinc, age, and sex in both groups. We conducted a cross-sectional study of 232 community-dwelling subjects aged between 35 and 60 years: 109 EH patients and 123 NH subjects. Serum FFA was determined by HPLC analysis. The data were analyzed by multivariate linear stepwise regression, stratified analysis, and correlation analysis. In men, EH patients had lower C22:6/C20:5 ratios (n-3 Delta6-desaturase activity index, 7.96+/-8.81 vs. 14.5+/-13.1, p<0.01), polyunsaturated fatty acid (PUFA), n-3 PUFA and polyunsaturated/saturated (P/S) ratios compared with male subjects without hypertension. There were no differences in women. Fasting serum FFA composition was significantly related to many variables, including waist/hip ratio, insulin sensitivity index, and serum zinc (all p<0.05 or <0.01) for all the subjects, and included both age- and sex-related differences (both p<0.05). Compared with NH, EH patients had lower levels of serum zinc (14.9+/-5.00 micromol L(-1) vs. 16.8+/-6.38 micromol L(-1), p<0.05). We concluded that EH patients had marked alteration in fasting serum FFA composition, which was affected by upper body obesity, insulin resistance, zinc deficiency, and high dietary fat, and that the differences were age- and sex-related.

Endocrine and Metabolic Effects of Rosiglitazone in Overweight Women With PCOS: Placebo-Controlled Study

Rosiglitazone is a member of the thiazolidinedione group of drugs that have, along with metformin, been used to treat insulin resistance in women with polycystic ovary syndrome (PCOS). Unlike metformin, rosiglitazone is a true insulin sensitizer that affects the transcription of various genes having roles in carbohydrate and lipid homeostasis. It significantly lowers plasma glucose levels in diabetic individuals. This double-blind, placebo-controlled study enrolled 30 overweight women with PCOS whose body mass index exceeded 25 kg/m 2 and whose average age was 29 years. All had symptoms of PCOS and'were confirmed by vaginal ultrasonography as having polycystic ovaries. Participants were randomized to receive either rosiglitazone (ROSI) or placebo (PLA), the former in a dose of 4 mg once a day for 2 weeks followed by 4 mg twice daily for 4 months. The 2 groups were clinically and endocrinologically comparable at the outset. Menstrual cycles had become more regular after 4 months of active treatment. There were no changes in the waist-to-hip ratio or in hirsutism scores. Serum levels of sex hormone-binding globulin increased in the treatment group. At the same time, levels of androstenedione, 17-hydroxyprogesterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate all decreased. On oral glucose tolerance testing, tolerance improved in the ROSI group and the peripheral insulin response decreased. M values, reflecting insulin sensitivity, improved in the ROSI group from 33 to 40 μmol/kg/min. Serum levels of testosterone and follicle-stimulating hormone did not change in either the ROSI or the PLA group. Fasting serum free fatty acid levels decreased significantly in women treated with ROSI. Treatment over 4 months with rosiglitazone significantly improved insulin resistance and menstrual cyclicity and, to some extent, hyperandrogenism in these overweight women with PCOS. This drug offers an effective and well-tolerated alternative for anovulatory women with PCOS who do not want to become pregnant.

Enhancement of insulin‐stimulated myocardial glucose uptake in patients with Type 2 diabetes treated with rosiglitazone

Peroxisome proliferator-activated receptor gamma (PPARgamma) activators have recently been identified as regulators of cellular proliferation, inflammatory responses and lipid and glucose metabolism. These agents prevent coronary arteriosclerosis and improve left ventricular remodelling and function in heart failure after myocardial infarction. Improvement in myocardial metabolic state may be one of the mechanisms behind these findings. The aim of this study was to investigate the effects of rosiglitazone on myocardial glucose uptake in patients with Type 2 diabetes. Placebo and metformin were used as control treatments. Forty-four patients were randomized to treatment with rosiglitazone (4 mg b.i.d.), metformin (1 g b.i.d.) or placebo in a 26-week double-blinded trial. Myocardial glucose uptake was measured using [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) and positron emission tomography (PET) during euglycaemic hyperinsulinaemia before and after the treatment. Rosiglitazone increased insulin-stimulated myocardial glucose uptake by 38% (from 38.7 +/- 3.4 to 53.3 +/- 3.6 micromol 100 g(-1) min(-1), P = 0.004) and whole body glucose uptake by 36% (P = 0.01), while metformin treatment had no significant effect on myocardial (40.5 +/- 3.5 vs. 36.6 +/- 5.2, NS) or whole body glucose uptake. Myocardial work as determined by the rate-pressure-product was similar between the groups. Neither treatment had any significant effect on fasting serum free fatty acids (FFA) but the FFA levels during hyperinsulinaemia were more suppressed in the rosiglitazone group (-47%, P = 0.02). Myocardial glucose uptake correlated inversely to FFA concentrations both before (r =-0.54, P = 0.002) and after (r = -0.43, P = 0.01) the treatment period in the pooled data. Furthermore, the increase in myocardial glucose uptake correlated inversely with interleukin-6 (IL-6) concentrations (r = -0.58, P = 0.03). In addition to the improvement in whole body insulin sensitivity, rosiglitazone treatment enhances insulin stimulated myocardial glucose uptake in patients with Type 2 diabetes, most probably due to its suppression of the serum FFAs.

Effects of identical weight loss on body composition and features of insulin resistance in obese women with high and low liver fat content.

Our objective was to determine how 8% weight loss influences subcutaneous, intra-abdominal, and liver fat (LFAT), as well as features of insulin resistance, in obese women with high versus low LFAT. A total of 23 women with previous gestational diabetes were divided into groups of high (9.4 +/- 1.4%) and low (3.3 +/- 0.4%) LFAT based on their median LFAT (5%) measured with proton spectroscopy. Both groups were similar with respect to age, BMI, and intra-abdominal and subcutaneous fat. Before weight loss, women with high LFAT had higher fasting serum insulin and triglyceride concentrations than women with low LFAT. At baseline, LFAT correlated with the percent of fat (r = 0.44, P < 0.05) and saturated fat (r = 0.45, P < 0.05) of total caloric intake but not intra-abdominal or subcutaneous fat or fasting serum free fatty acids. Weight loss was similar between the groups (high LFAT -7.4 +/- 0.2 vs. low LFAT -7.7 +/- 0.3 kg). LFAT decreased from 9.4 +/- 1.4 to 4.8 +/- 0.7% (P < 0.001) in women with high LFAT and from 3.3 +/- 0.4 to 2.0 +/- 0.2% (P < 0.001) in women with low LFAT. The absolute decrease in LFAT was significantly higher in women with high than low LFAT (-4.6 +/- 1.0 vs. -1.3 +/- 0.3%, P < 0.005). The decrease in LFAT was closely correlated with baseline LFAT (r = -0.85, P < 0.001) but not with changes in the volumes of intra-abdominal or subcutaneous fat depots, which decreased similarly in both groups. LFAT appears to be related to the amount of fat in the diet rather than the size of endogenous fat depots in obese women. Women with initially high LFAT lost more LFAT by similar weight loss than those with low LFAT, although both groups lost similar amounts of subcutaneous and intra-abdominal fat. These data suggest that LFAT is regulated by factors other than intra-abdominal and subcutaneous fat. Therefore, LFAT does not appear to simply reflect the size of endogenous fat stores.

Selective mobilisation of fatty acids from human adipose tissue

Background: Adipose tissue is a storage organ for dietary fat. During fasting, fatty acids are released into serum as free fatty acids (FFA). Experimental studies indicate that fatty acids are selectively mobilised from adipose tissue into serum. The aim of this study was to investigate whether the composition of the serum FFA fraction reflects selective mobilisation in the fasting state in humans. Methods: The fatty acid composition of fasting serum FFA and adipose tissue were analysed from 112 patients with myocardial infarction and 107 healthy control subjects using gas–liquid chromatography. The subjects’ habitual diet was analysed using a food-frequency questionnaire. Results: Significant correlations were found between serum FFA and adipose tissue, particularly for the percentage content of linoleic acid ( r=0.73), eicosapentaenoic acid ( r=0.68), α-linolenic acid ( r=0.67) and palmitoleic acid ( r=0.60). Percentage contents of palmitic, stearic, linoleic, α-linolenic, eicosapentaenoic and docosahexaenoic acid were higher in serum FFA than in adipose tissue, whereas oleic and palmitoleic acid were relatively more abundant in adipose tissue. This may indicate that the former group of fatty acids is preferentially mobilised from adipose tissue into serum. High correlations for polyunsaturated fatty acids were observed between percentage contents of dietary and adipose tissue fatty acids. The correlation of fatty acids between diet and serum FFA was weak, but a tendency towards higher correlations for polyunsaturated fatty acids was observed. Conclusions: Our findings are compatible with the hypothesis that, in the fasting state, fatty acids are selectively mobilised from adipose tissue into serum FFA.

Effects of capsaicin on abdominal fat and serum free-fatty acids in exercise-trained rats

This study was undertaken to determine whether capsaicin may influence abdominal fat deposition and circulating free-fatty acids in exercise-trained rats. In addition, the contribution of beta-adrenergic stimulation to capsaicin-induced changes in serum free-fatty acids was examined. All rats (n=144) were submitted to a treadmill exercise protocol for 14 days. During the first seven days, they were all fed ad libitum with a diet supplemented with capsaicin. Two thirds of rats maintained this diet during the last seven days (capsaicin-diet group) whereas the other rats were pair fed without capsaicin intake (control-diet group). At the end of the protocol, the acute effect of beta-adrenergic blockade (propranolol) on serum free fatty acid concentrations was tested in half of the capsaicin-diet group (propranolol-capsaicin-diet group). A placebo was injected to all other rats, i. e., the other half of rats in the capsaicin-diet group (placebo-capsaicin-diet group) and those in the control-diet group. Epididymal adipose tissue weight was significantly lower in the placebo-capsaicin-diet and propranorol-capsaicin-diet groups than in the control-diet group (p<0.0001). This change was accompanied by a higher level of fasting serum free fatty acids in the placebo-capsaicin-diet group. These results show that under conditions of pair feeding and exercise training, capsaicin intake induces a significant negative energy balance after only one week of treatment. This is associated with an increase in circulating free-fatty acids which is mediated by beta-adrenergic stimulation.

Fasting Serum Free Fatty Acids and Triglycerides are Increased Before 20 Weeks of Gestation in Women who Later Develop Preeclampsia

Objective: The null hypothesis of this study was that there was no difference in fasting serum concentrations of free fatty acids (FFA) and triglycerides (TG) before 20 weeks of gestation in women who later develop preeclampsia, compared to women with uneventful pregnancies.Methods: Healthy primigravida, n = 510, provided fasting blood samples at 16-18 weeks of gestation. Nineteen of these later developed preeclampsia. Nineteen matched controls were selected from the remaining 491 individuals. Blood samples were also obtained from 16 patients with manifest preeclampsia and from 16 control women with uncomplicated pregnancies. Concentrations of FFA and TG, and the lipolytic activity in maternal serum were measured.Results: In patients with manifest preeclampsia, serum levels of FFA and TG, and lipolytic activity were significantly increased compared to women with normal pregnancies. The group of 19 women who later developed preeclampsia had higher serum FFA and TG concentrations at 16-18 weeks of gestation compared to a matched control group: FFA 0.50 0.15 vs. 0.34 0.11 mmol/L (P < 0.001) and TG 1.3 0.5 vs. 0.9 0.3 mmol/L (P = 0.003).Conclusion: We provide for the first time evidence that fasting serum free fatty acids and triglycerides are increased before 20 weeks of gestation in women who later develop preeclampsia.

The longitudinal effect of inhibiting fatty acid oxidation in diabetic rats fed a high fat diet.

This study was designed to examine the time-course of response to inhibition of fatty acid (FA) oxidation in rats rendered mildly diabetic with streptozotocin and fed a high fat diet (50% of energy derived from fat). Etomoxir, a specific carnitine palmitoyltransferase (CPT-1) inhibitor, was administered subcutaneously (12.5 mg/kg) to inhibit long chain fatty acid oxidation. Diabetic and non-diabetic control rats were maintained on the high fat diet. Following an overnight fast, glucose, free fatty acid (FFA) and triglyceride (TG) concentrations were determined after three days, one week and four weeks of treatment. The effect of Etomoxir treatment in reducing fasting glucose concentrations was not evident until after one week, while fasting FFA and TG concentrations were already reduced after three days treatment. All of these changes were maintained over the four week period (P less than 0.001), resulting in reduced levels of fasting plasma glucose (17.6 +/- 2.4 vs 22.3 +/- 1.9 mmol/l), fasting plasma TG (0.32 +/- 0.07 vs 0.98 +/- 0.14 mmol/l) and fasting serum FFA (1.52 +/- 0.26 vs 3.51 +/- 0.69 mEq/l). In addition, the improvements in glucose and lipid levels were accompanied by restored rates of growth towards that of non-diabetic control rats. These results suggest that the short term inhibition of FA oxidation improves fasting glucose, FFA and TG concentrations in diabetic rats fed a high fat diet.

Biochemical and physiological responses to metabolic stimuli in Friesian calves of differing genetic merit for milk production

ABSTRACTChanges in blood metabolite and insulin concentrations in response to metabolic stimuli were evaluated as potential predictors of dairy merit. Calves of high or low genetic merit for milk production were subjected to the stress of: simulated feeds by injection of sodium propionate (0·5 mmol/kg body weight), a short fast and short-term cold exposure. Responses of insulin, free fatty acids, urea, glucose and D-β-hydroxybutyrate were determined by serial blood sampling.Injections of sodium propionate did not greatly affect blood metabolite concentrations but did sharply increase insulin concentrations; no difference in response between high and low lines was observed. During fasting serum free fatty acid and D-β-hydroxybutyrate concentrations were greatly increased but no variation due to line was observed. Urea concentrations were also greatly increased during fasting and in this case animals of high dairy merit showed a considerably smaller increase than animals of low dairy merit. Heart rates decreased by one-third during the fast but no variation due to line was apparent;during refeeding high dairy-merit animals had lower heart rates than low-merit animals.Short-term cold exposure did not significantly alter plasma insulin or metabolite concentrations.These results are discussed in relation to previous findings and it is concluded that serum urea concentrations during a fast may provide the basis for a useful and robust predictor of dairy merit in young animals.

Effect of human growth hormone on fatty acid composition of serum lipids

The effects have been studied of human growth hormone (HGH) and of prolonged fasting on the fatty acid composition in serum of free fatty acids (FFA), triglycerides, cholesteryl esters and phospholipids. The serum fatty acid pattern was also studied in 3 acromegalic women.Following one injection of HGH, serum FFA concentrations rose and were highest at 8 h. This was mainly due to increased free oleic acid. Serum phospholipid concentrations fell and were lowest at 4 h.Prolongation of an overnight fast by 8 h also induced significant increases in serum FFA concentrations with an increase in free oleic acid, but of a smaller magnitude than after HGH injection; decreases occurred in free stearic and linoleic acids. The percentage level of phospholipid palmitate increased and that of linoleate decreased. In addition, the percentage level of triglyceride stearate decreased.When HGH was administered over 3 days, fasting serum FFA increased only on the 2nd day of treatment. The concentrations of serum phospholipid decreased steadily. An increase occurred in the percentage levels of triglyceride palmitate, cholesteryl oleate and phospholipid linoleate and eicosatrienoate. A decrease occurred in the percentage level of phospholipid oleate.Acromegalic patients had higher percentage levels of saturated acids in free and triglyceride fatty acids compared with normal controls. The high percentage of triglyceride saturated acids was the only characteristic that increased endogenous secretion and exogenously administered HGH had in common.

SEX DIFFERENCE IN SERUM-FREE FATTY ACID LEVELS IN DIABETIC SUBJECTS.

Fasting serum-free fatty acid (FFA) and blood glucose levels were measured in 57 healthy subjects and in 80 untreated diabetic subjects. The response of the serum-FFA level to the rapid intravenous injection of glucose (1.0 g/kg0.7) was examined in 33 healthy subjects and in 57 untreated diabetic subjects. The effect of treatment of diabetes with Lente insulin, sulfonylureas and phenformin (phenethyl biguanide) upon the serum-FFA levels and responsiveness was examined in 16, 4 and 7 subjects, respectively. A distinct sex difference was observed in both the fasting serum-FFA level and its responsiveness to glucose. In healthy men the fasting serum-FFA level was lower, and its response to glucose less, than in healthy women. In diabetic men the fasting serum-FFA level did not increase as the fasting blood glucose level increased, and was only slightly elevated even when severe fasting hyperglycemia was present. In diabetic women the fasting serum-FFA level did increase as the fasting blood glucose level inc...